Abstract: A bobbin rotating on a spindle in order to draw slivers into rovings coacts with a presser foot which is swingable in an eccentric wing of a flyer journaled on a fly frame above the bobbin and coaxial therewith. The inward swing of the presser foot is limited to a distance from the spindle axis which is slightly less than the radius of the bobbin so as to enable an outward camming of that foot, against the force of a biasing spring inside the wing, with the aid of a beveled surface on the presser foot and/or on the bobbin top when the spindle carrying an empty bobbin initially rises relatively to the fly frame.